1. Field of the Invention
The present invention relates to a cooling system, and in particular to a dual-loop circulation cooling system for an oven of a liquid crystal manufacture process.
2. The Related Arts
In a contemporary liquid crystal manufacture process, various steps, such as baking, curing, and annealing, require an oven for heating. Referring to FIG. 1, a schematic perspective view showing structure of a known oven used in a liquid crystal manufacture process is given. In a known oven 10 used in a contemporary liquid crystal manufacture process, to maintain cleanliness level of the oven 10, the oven 10 is often provided with an air supply/exhaust system, which draws in clean air through a purification pipe 11 in order to form a positive pressure inside the oven 10 and discharges air outward through air exhaust pipes 12. The direction of air flow is indicated by arrows. Further, the oven 10 has a shielding plate side 13 and a rear maintenance gate side 14, both of which are openable for access to the interior of the oven 10.
To ensure the quality of liquid crystal, the oven must be frequently maintained. Heretofore, to conduct maintenance of an oven used in a liquid crystal manufacture process, the internal temperature of the oven must be first lowered before manual maintenance operation can be carried out. However, the conventional way of lowering oven internal temperature is natural cooling, and it generally takes a long period of time (approximately 6 hours) to have temperature dropping from a high level of 150° C. (illustrative temperature) down to a level below 60° C. This becomes a bottle neck for the time-consuming operation of maintaining an entire liquid crystal manufacture line.
This is simply because the process of cooing takes a large amount of time and during such a period, due to such a high temperature, it is not possible for operators to carry out the desired maintenance operation. This is a period of dead time. Due to the excessive length of the dead time, the overall time period of oven maintenance is over extended. It usually takes at least a whole day to maintain a single oven and this makes the maintenance of the whole manufacture line extremely long.